Noun. This is a code word for shitting your trousers in the workplace. Generally employed in conversation when an unwanted third set of ears is present during a personal conversation about shitting your pants at work. The speaker will tactically say they "had a brownie" which means that they shit their pants accidentally while at work.

X: "Hey Jane, how's your morning been?"
Y: "Well it was going pretty good until around nine I had a brownie."
X: "Damn. A brownie?"
Y: "Yes I had a quart of Miller High Life last night during the game and a pot of coffee to on top of it this morning on the way to work. Sure as hell...that combo lead to my having a brownie when I got here."